A study in Bangladesh links heat and humidity with increased rates of anxiety and depression.
Climate-related events have been confirmed to have a negative effect on mental health, according to new research published this week.
The study looked at the effect of heat, humidity and flooding on rates of depression and anxiety in Bangladesh - the seventh most vulnerable country in the world to climate change.
An estimated 4.4 per cent of people around the world are thought to have depression. In Bangladesh, this figure was considerably higher at 16.3 per cent.
Anxiety levels in the country were also higher (6 per cent) compared to the rest of the world (3.6 per cent).
Researchers say the findings of the study could be used to narrow down the wider effect of climate change on mental health.
“As climate change worsens, temperatures and humidity will continue to increase, as will natural disasters, such as extreme flooding, which portends worsening impact on our collective mental health, globally,” says the study’s lead author Syed Shabab Wahid, an assistant professor in the department of global health at Georgetown University’s School of Health.
Heat and humidity have an alarming effect on mental health
The study measured climate variables at 43 weather stations in Bangladesh for seasonal changes in temperature and humidity, as well as noting where people were exposed to flooding.
Two surveys were then conducted in rural and urban areas to assess depression and anxiety in adults.
It revealed that heat, humidity and climate-related events had an alarming effect on the mental health of the respondents.
People experiencing one degree Celsius higher temperatures were found to be 21 per cent more likely to have an anxiety disorder. They were also 24 per cent more likely to have both depression and anxiety together.
The study also found a link between increased humidity in the air and a higher chance of the participants reporting both depression and anxiety.
Exposure to worsening flooding linked to climate change increased the odds of poor mental health. Depression increased by 31 per cent, anxiety by 69 per cent and the presence of both conditions by 87 per cent.
Is the study a warning for other nations?
Researchers say the study isn’t enough to see the impact of major climate change but it does show how even small changes in weather linked to climate change can affect mental health.
Wahid says they now plan to conduct further research in Bangladesh and globally to “narrow down the causes and effects of climate changes on mental health.”
The study’s authors note that the findings are particularly concerning for countries where people are exposed to heat through daily labour or activities. Women, older populations and people with disabilities were especially vulnerable to the impacts of climate change on mental health.
“We have now established a high-water mark that alas could soon be eclipsed for how climate can impact mental health in a highly vulnerable country,” Wahid explains.
“This should serve as a warning for other nations.”